//定位浮动
.f-l{
  float: left;
}
.f-r{
  float: right;
}
.clean{
  clear: both;
}

.va-m{
  vertical-align: middle;
}
.va-b{
  vertical-align: bottom;
}
.c-w{
  color:#fff;
}
.c-r{
  color:red;
}
.bg-w{
  background: #fff;
}